| A | B |
|---|
| What Kingdom are we studying | Animalia |
| Subkingdom | Eumetazoa |
| Phylum | Arthropoda |
| What does Arthropoda mean? | jointed foot |
| ex. of Arthropods | crabs insects spiders centipedes |
| how many animals are there in this phylum | 3/4 |
| common characteristics of arthropods | jointed appendage, segmented body, exoskeleton, similar systems |
| jointed appendages | extensions of the body |
| examples of appendage | legs antennae |
| Segmented body | early forms had one pair of appendgaes per segment ( evolution resulted in lost or reduced numbers of appendages |
| exoskeleton general | hard external covering provides protection and support |
| similar systems of arthropods | ventral nervous system; open circulatory system; sensory systems |
| exoskeleton in detail | hard outer covering; gives protectoin; support; h20 conservation; great strength and versatility; made of protein and carbohydrate; chitin - tough carbohydrate |
| three layers of the exoskeleton | waxy outer layer hard middle layer and flexible inner laer |
| waxy outer layer | repels water |
| hard middle layer | provides protection |
| flexible inner layer | flexible at joints, allows for locomotion |
| what are the three layers of the exoskeleton secreted by | the epidermis |
| what are examples of things chitin is used for | sutures, artificial skin, contact lenses |
| muscles | attached to inside of exoskeleton and on either side of joints; allows for a wide range of movement form in bundles move by muscle contraction and relaxation |
| ecdysis | the shedding of exoskeleton to allow for growth |
| molting | ecdysis |
| 5 steps to molting | 1. grow until pressure builds up; 2. epidermis to secrete a hormone that dissolves exoskeleton; 3. at the same time the epidermis is generating a new exoskeleton, using some of the digested edxoskeleton; 4. old skeleton is flexible at first then once it is exposed to either air or hto it hardens |
| what are the drawbacks to molting | vunerable - shell is soft so they hide when molting to protect themselves when molt they smotimes lose appendages |
| evolution - how long ago did ancestral forms show up | 600 mya |
| what happened 600 mya? | ancestral forms showed uyp |
| what are the four subphylums | trilobita, crustacea, chelicerata, uniramia |
| trilobita | trilobites - extinct |
| crustacea | shrimp lobster crab waterflee crayfish |
| chelicerata | spiders scorpions ticks mites horseshoe crabs |
| uniramis | only group to evolve on land centipedes millipedes all insects |
| what are 2 ways that the subphylums are distinguished form each otehr? | embryological develpment and morphology |
| morphological diffence of trilobits | extinct |
| morph diff of chelicerates | no antennae; pincer - likee mouth parts - chilicerae |
| morph diff of crustaceans | branched appendages; cehewing mouth parts - mandilbles |
| morph diff of uniramia | unbranched appendages; mandibles; antennae |
| What are some examples of the subphylum crustacea | crayfish pill bugs sowbugs water flees |
| characteristics of crustaceans | hard exoskeletons; mostly aquatic members; most small |
| characteristics of sowbugs and pill bugs | terrestrial; 7 identical pairs of legs - isopods (same feet); live in damp areas where gills can stay moist |
| why is the crayfish good to study? | because they are large and abundant |
| what are the 2 body structures of the crayfish? | cephalothroax and abdomen |
| cephalothorax | head and thorax fused |
| how many segments are in the cephalothorax | 13 segments |
| what is the cephalothorax covered by | hard carapace |
| how many segments are in the abdomen | 7 |
| what is the last segment of the abdomen | telson |
| telson | the flat triangular section at tail |
| abdominal muscles | powerful can contract causing rapid movement backward |
| how many pairs of appendages are attaced to each segment? | 1 |
| appendage modifications | antennules, santenna, mandible, maxilla, maxillipeds, chelipeds, walking legs, swimmerets, uropods, telson |
| chelipeds in eating | trap food |
| maxilla and maxillipeds | tear food apart |
| mandibles | chew food |
| esophagus | i don't know |
| stomach | chitinous teeth grind up food into fine paste |
| digestive gland | absorb paste mixed calcium digestive juices |
| intesteine | passageway of undigested material |
| anus | food leave |
| green glands | excretory organs that remove wastes from blood but retain salts |
| gills | attached to walking legs protected by the carapace |
| how do crayfish breathe | as crayfish walks and feeds, gill bailers help move H2O over gills |
| 5 parts to nervous system | brain ventral nerve cord - from brian to tail nerve impulses travel to and from the nerve cord via ganglion nerves connect sense receptors to brian sense receptores are in antennules, eyes, and antenae |
| eyes | set on movable stocks |
| compound eye | 2o00 light sensitive lenses, highly sensitive to light and motion but can only form a crude image |
| statocysts | cells that contain calcium carbonate |
| how to statocysts help the crayfish | helps crayfish to monitor its position in the environment |
| when do crayfish mate | inthe fall |
| steps to mating | male uses 1st and 2nd swimmerets ti transfer sperm to the females seminal receptacle, female store sperm until spring; female lays eggs, as teh eggs are traveling out the genital proe, they mix with the stored sperm; eggs attach to females last 3 sets of legs by a stcky substance; 6 wks later they hatch and go through several larval stages; young looklike mini adults |
| how often to crayfish molt | 7xs the 1st year and 2xs for the next 2 - 3 years |
